欧美国家针叶树容器苗生产与启示

针叶树是芬兰、瑞典、挪威、美国、加拿大等欧美国家主要的商品林树种。容器苗是针叶树重要的育苗类型。与裸根苗比较，容器苗具有育苗周期更短、造林季节可延长、苗木适应性更广、苗木质量更一致的优点。因此，容器育苗成为精准林业发展的必然趋势。为了借鉴欧美容器育苗的技术方法，提高我国容器苗的质量，为我国针叶树容器苗发展提供参考，文中主要从4个方面综述了欧美国家检测与提高苗木质量的方法，即列举了针叶树常用的苗木质量检测指标，总结了育苗容器与育苗基质的改良进展，介绍了养分、水分、光照与温度等培养条件的优化手段，简要概述了容器苗病虫害防控的进展，提出了我国相关树种容器苗生产的启示与借鉴。     

农业技术模式转换与对策探讨——以河南省欠发达平原农业区为例

面对当前农村劳动力转移给农业发展带来的挑战和机遇,转换农业技术模式尤为重要.采用理论分析和调查访谈相结合的方法,得出河南欠发达平原农业区农业技术模式转换必须结合本地实际,遵循诱致性轨迹,注重转换过渡模式,即以农民社会资本为纽带进行土地流转,形成土地适度渐进规模经营,以村集体、宗族等为核心发展种子、生物科技、中小型机械设...     

A市低收入边缘群体特征及针对性减贫路径探讨

【目的/意义】随着脱贫攻坚进程不断深入,低收入边缘群体问题日益突出,通过分析低收入边缘群体特征及其存在的问题,探索更高效的帮扶手段,为其他经济发达地区提供借鉴。【方法/过程】基于A市249户低收入边缘群体的调查数据,运用文献法、问卷调查和重点访谈法等研究方式,研究调查低收入边缘群体脱贫攻坚落实情况。【结果/结论】基于对问题的分析,提出准确甄别低收入边缘群体,完善收入核准机制;充分挖掘社会资源,聚焦扶志立业工作;加强基础工作指导,提升基层干部信心;涵养乡风文明,重塑家庭责任意识等对策建议。     

国外保护地生态旅游评价研究进展

保护地是世界生态旅游活动的主要场所，近年来，随着对生态研究的深入，国外有关保护地生态旅游评价的研究逐步增多。本文通过对相关文献的梳理，发现国外有关保护地生态旅游评价的研究可以概括为三方面：（1）保护地生态旅游评价原则与标准的探讨；（2）保护地生态旅游评价主体内容研究；（3）保护地生态旅游的评价方法与指标体系。综合来看，国外保护地生态旅游评价研究具有5方面显著特点值得国内学者学习和借鉴：（1）评价研究逐步深入；（2）多种方法综合应用；（3）强调一手资料的获取和使用；（4）重视社区在评价研究中的参与；（5）保护地生态旅游评价的根本指导思想为可持续发展理论。     

加强南南合作是肉食行业发展的趋势

中国已经加入世界贸易组织,世界格局发生变化.中国政府团结广大发展中国家共同发展,肉食行业面临广泛的发展空间.     

从价格角度看我国木工机械走向国际市场的开发方向

从2004年米兰国际木工机械展览会展出的发达国家低档木工机械的市场价格分析出发，分析我国和发达国家木工机械的差距，从中探索我国木工机械走向国际市场的新产品开发方向，提出我国木工机械走进国际市场后，其产品开发的新设想。     

花岗岩黄红壤杉木幼林施肥连年生长效应

１９９１￣１９９５年试验结果表明，在江西分宜花岗岩残积物发育的黄红壤上，杉木幼林施Ｎ、Ｐ、Ｋ及配合处理，使树高、胸径、蓄积总生长量指标分别达到５．６７￣６．５９ｍ、８．３５￣９．２８ｃｍ、６７．９２２￣９６．４１ｍ＾３／ｈｍ＾２，较对照增长５．６％￣２０．２％、７．４％￣１７．５％、２１．６％￣５６．２％。在各种施肥处理中，以５０ｋｇ／ｈｍ＾２Ｐ２Ｏ５的效果最佳，其连年生长量效应显著持续到第５年；     

跨区作业经济效益影响因素剖析

根据2004年跨区作业调查,计算了联合收割机跨区机收的经济效益,并着重指出了跨区作业经济效益下降的实际问题;通过深入分析其中的原因,指出影响跨区作业经济效益的两大主要因素,是信息系统不完善和散机的无序流动。     

Influence of Cultural Practices on the Performance of Long Level Basins in Egypt

Several field studies were conducted tobetter understand the influence of culturalpractices, inflow rate and field conditionson the performance of modern surfaceirrigation systems in Egypt. Field datawere collected on wheat and cotton underEgyptian conditions in order to estimateinfiltration, roughness and performanceparameters. Tests were made with a varietyof inflow rates and a variety ofcross-section shapes (flat or furrowed andseveral furrow spacings). These studiesprovide information on expected values ofinfiltration and roughness parameterstypical of cracking clay soils in the NileDelta, as well as guidelines andrecommendations for use of long-levelbasins in Egypt.     

Enhancing the Simplified Surface Energy Balance (SSEB) approach for estimating landscape ET: Validation with the METRIC model

Evapotranspiration (ET) can be derived from satellite data using surface energy balance principles. METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is one of the most widely used models available in the literature to estimate ET from satellite imagery. The Simplified Surface Energy Balance (SSEB) model is much easier and less expensive to implement. The main purpose of this research was to present an enhanced version of the Simplified Surface Energy Balance (SSEB) model and to evaluate its performance using the established METRIC model. In this study, SSEB and METRIC ET fractions were compared using 7 Landsat images acquired for south central Idaho during the 2003 growing season. The enhanced SSEB model compared well with the METRIC model output exhibiting an r² improvement from 0.83 to 0.90 in less complex topography (elevation less than 2000 m) and with an improvement of r² from 0.27 to 0.38 in more complex (mountain) areas with elevation greater than 2000 m. Independent evaluation showed that both models exhibited higher variation in complex topographic regions, although more with SSEB than with METRIC. The higher ET fraction variation in the complex mountainous regions highlighted the difficulty of capturing the radiation and heat transfer physics on steep slopes having variable aspect with the simple index model, and the need to conduct more research. However, the temporal consistency of the results suggests that the SSEB model can be used on a wide range of elevation (more successfully up 2000 m) to detect anomalies in space and time for water resources management and monitoring such as for drought early warning systems in data scarce regions. SSEB has a potential for operational agro-hydrologic applications to estimate ET with inputs of surface temperature, NDVI, DEM and reference ET.